ExperimentName: Murine model of PDE6A loss-of-function (Pde6Anmf363/nmf363)

NonHumanModel: Mus musculus

GeneAlteration: Mice were found to develop retinal degeneration due to a homozygous missense variant (2159G>A) at codon 670 substituting glycine for aspartic acid.

ModelPhenotype: HP:0030609 (Photoreceptor layer loss on macular OCT), HP:0030478 (Abnormal amplitude of dark-adapted bright flash electroretinogram)

HumanPhenotype: HP:0011463 (Childhood onset), HP:0000662 (Nyctalopia), HP:0007994 (Peripheral visual field loss), HP:0000543 (Optic disc pallor), HP:0007843 (Attenuation of retinal blood vessels), HP:0007737 (Bone spicule pigmentation of the retina), HP:0000654 (Decreased light- and dark-adapted electroretinogram amplitude), HP:0007984 (Electronegative electroretinogram)

ModelEvidence: This mutation caused photoreceptor outer nuclear layer outer segment thinning (Figures 2C, 2D, 7), decreased dark-adapted bright flash ERG amplitude (Figure 2E), and decreased cGMP/PDE activity (Figure 3C).

ModelVariant: The model does not harbor a variant equivalent to one from the human patients, but rather has a mutagenesis-induced missense variant disrupting Pde6a leading to partial loss-of-function.

ExperimentName: Targeted disruption of Lrp5 in mice

NonHumanModel: Mus musculus

GeneAlteration: Model animals were subjected to targeted disruption of Lrp5 by inserting an IRES-LacZ-Neomycin cassette to replace the region encoding the extracellar domain, starting at amino acid 373.

ModelPhenotype: HP:0004349 (Reduced bone mineral density), HP:0410280 (Pediatric onset), decreased osteoblast proliferation, HP:0007968 (Remnants of the hyaloid vascular system), failure of macrophage-mediated endothelial cell apoptosis

HumanPhenotype: HP:0000939 (Osteoporosis), HP:0011463 (Childhood onset), HP:0000541 (Retinal detachment), HP:0007968 (Remnants of the hyaloid vascular system), HP:0008046 (Abnormal retinal vascular morphology), HP:0000618 (Blindness), HP:0001249 (Intellectual disability), HP:0020110 (Bone fracture), HP:0000938 (Osteopenia), HP:0000926 (Platyspondyly)

ModelEvidence: Model animals subjected to targeted disruption of Lrp5 resembled human patients in that they exhibited reduced bone mineral density in the post-natal stage (Figs. S2, 3A), decreased osteoblast proliferation (Fig. 4), delayed ossification (Fig. 5), and remnants of the hyaloid vascular system due to failure of macrophage-mediated endothelial cell apoptosis (Fig. 8).

ModelVariant: The model features disruption of the wild-type Lrp5 gene, but not a mutation equivalent to a human variant.

ExperimentName: Retinal dystrophy in dogs is caused by Rpe65 loss of function.

NonHumanModel: Canis familiaris

GeneAlteration: Swedish Briard / Briard Beagle dogs exhibit a biallelic 485delAAGA variant in the RPE65 locus that triggers a frameshift predicted to disrupt ~71% of the protein product.

ModelPhenotype: HP:0007642 (Congenital stationary night blindness), HP:0007663 (Reduced visual acuity), HP:0000618 (Blindness), HP:0007703 (Abnormality of retinal pigmentation), HP:0000556 (Retinal dystrophy), HP:0030483 (Reduced amplitude of dark-adapted bright flash electroretinogram a-wave), HP:0007984 (Electronegative electroretinogram), HP:0030479 (Abnormal amplitude of light-adapted flicker electroretinogram)

HumanPhenotype: HP:0000662 (Nyctalopia), HP:0000529 (Progressive visual loss), HP:0000618 (Blindness), HP:0030479 (Abnormal amplitude of light-adapted flicker electroretinogram), HP:0030474 (Undetectable dark-adapted electroretinogram)

ModelEvidence: The model system recapitulates the human phenotype in that the dogs exhibit severe vision loss (Table 1 in PMID: 2804031, describing the same animal model), structural abnormalities of the RPE (PMID: 7851218, studying the same animal model), and similar ERG abnormalities (Figures 2 and 3 in PMID: 2804031). Similar to the human patient families, the heterozygous individuals are unaffected (Figure 1 in this publication).

ModelVariant: The dogs harbor a spontaneously occurring frameshift variant in exon 5 of 14 (485delAAGA), rather than a targeted mutation equivalent to a particular human patient variant.

ExperimentName: Rpe65 homozygous knockout abolishes rod photoreceptor function and disrupts RPE metabolism in mice.

NonHumanModel: Mus musculus

GeneAlteration: Rpe65 homozygous knockout was generated by replacing the 5' flanking region and the first three exons of Rpe65 with a PGK-Neo cassette.

ModelPhenotype: HP:0000479 (Abnormal retinal morphology), HP:0030469 (Abnormal dark-adapted electroretinogram), HP:0030483 (Reduced amplitude of dark-adapted bright flash electroretinogram a-wave), HP:0007984 (Electronegative electroretinogram)

HumanPhenotype: HP:0000662 (Nyctalopia), HP:0007688 (Undetectable light- and dark-adapted electroretinogram), HP:0001098 (Abnormal fundus morphology), HP:0000529 (Progressive visual loss)

ModelEvidence: The model system recapitulates the human phenotype in that the mice exhibit progressive onset of abnormalities in retinal morphology (specifically photoreceptor outer segment loss, Figures 2a-2e), accompanied by reduced responses in dark-adapted (Figure 4) but not light-adapted (Figure 5) ERG. These ERG results are characteristic of abolished rod function. The mice also recapitulate the molecular features of the human patients in that retinal esters accumulate in the retinal pigment epithelium of the mice (HPLC data in Figures 8a-8c).

ModelVariant: The model disrupts the entire Rpe65 locus rather than introducing a mutation equivalent to a human patient variant.

ExperimentName: "Prpf4 silencing in zebrafish causes defects in visual function."

NonHumanModel: Danio rerio

GeneAlteration: The model animals have been subjected to morpholino-based knockdown of Prpf4, the zebrafish ortholog of human PRPF4.

ModelPhenotype: Nystagmus HP:0000639, Abnormality of ocular smooth pursuit HP:0000617

HumanPhenotype: Constriction of peripheral visual field HP:0001133, Reduced visual acuity HP:0007663,, Decreased light- and dark-adapted electroretinogram amplitude HP:0000654. Retinal degeneration HP:0000546, Macular degeneration HP:0000608, Optic disc pallor HP:0000543, Attenuation of retinal blood vessels HP:0007843, Pigmentary retinopathy HP:0000580

ModelEvidence: Morpholino-based incomplete knockdown of the Prpf4 gene circumvents the lethality of complete silencing and causes optokinetic nystagmus with a significantly reduced number of saccades (Fig. 5B, 5C, 5D). Immunohistochemistry showed that retinal morphology showed mostly normal retinal layering but decreased rhodopsin staining in the photoreceptor cell layer (Figs. 5E–5H). Photoreceptor outer segments were primarily affected, but with unaffected cell body morphology (Figs. 5I and 5J). This phenotype was a complete match for the zebrafish with Prpf31 loss/. Semi-quantitative RT–PCR analysis of the RP-relevant transcripts opn1lw1, opn1mw1, gnat2, irx6a, rx3, crx and rhodopsin as well as the controls gapdh and lsm7 showed a very similar pattern of down-regulation in both Prpf31- and Prpf4-deficient animals (Fig. 5W). The phenotype was dose-dependent and could be rescued by co-injection of Prpf4 mRNA (Fig. S2).

ModelVariant: This model did not introduce a disease-associated variant known from an affected human patient, but rather studied the effects of heterozygous loss of the gene product.

ExperimentName: Knockout mouse model of Impg1

NonHumanModel: Mus musculus

GeneAlteration: The mouse model harbors a deletion of exon 6, resulting in disruption of reading frame and loss of Impg1 protein either in the heterozygous or homozygous state.

ModelPhenotype: HP:0025158 (Hyperautofluorescent retinal lesion), HP:0000512 (Abnormal electroretinogram, specifically attenuated responses), HP:0030609 (Photoreceptor layer loss on macular OCT, described as degeneration with loss of 11-cis-retinal signal), HP:0007703 (Abnormality of retinal pigmentation, specifically disruption of RPE cells and the IPM)

HumanPhenotype: HP:0007754 (Macular dystrophy), HP:0007769 (Peripheral retinal degeneration), HP:0032037 (Mildly reduced visual acuity, progressive), HP:0008179 (Decreased Arden ratio of electrooculogram), HP:0030505 (Nummular pigmentation of the fundus)

ModelEvidence: The model exhibits phenotypes consistent with a critical role of Impg1 in photoreceptor maintenance. Phenotypes included hyperpigmented and sometimes autofluorescent subretinal deposits that were present at 9 months of age (Figure 2B) and increased by 14 months of age (Figure 2C) that were localized between the photoreceptor outer segment and the RPE (Figure 2D). Some images showed nummular pigmentation of the fundus (Figure 2E). Interestingly, attenuation of ERG response was first noted at 9 months and pronounced at 14 months (Figure 3A), which is consistent with the findings from an independent mouse model that showed less dramatic findings at earlier 5 month and 8 month time points (PMID: 32265257). Scotopic ERG was more affected than photopic ERG (Figure 3B). Retinal thickness was also reduced in the outer layer relative to the inner layer (Figure 3C). Retinoid generation was also progressively abnormal (Figure 4), indicating that photoreceptors might be lost. The IPM was also disorganized at 14 months (Figure 5), with cellular material accumulating in the IPM consistent with cell death (Figure 6).

ModelVariant: The model harbors a knockout allele disrupting Impg1, rather than a specific variant from a human patient.

ExperimentName: Homozygous disruption of the chicken ortholog of GUCY2D

NonHumanModel: Gallus gallus domesticus

GeneAlteration: The null allele of the chicken Rd gene (orthologous to human GUCY2D) exhibits a rearrangement in which a 723-bp region corresponding to exons 4-7 has been replaced by an in-frame insertion of 81-bp fragment likely derived from exon 9. This deletes the transmembrane domain and is predicted to result in complete inactivation of the enzyme. This variant has been studied in the homozygous state.

ModelPhenotype: HP:0007875 (Congenital blindness), HP:0000654 (Decreased light- and dark-adapted electroretinogram amplitude), Optokinetic reflex,

HumanPhenotype: HP:0007663 (Reduced visual acuity), HP:0007688 (Undetectable light- and dark-adapted electroretinogram), HP:0007703 (Abnormality of retinal pigmentation)

ModelEvidence: Chickens harboring the null variant in a homozygous state have dramatically lower levels of cGMP in the retina (Figure 1) and absent expression of GC1, the GUCY2D ortholog (Figure 2). Rod and cone photoreceptor cells develop normally, but have little to no function according to ERG. This is similar to the normal fundus appearance in LCA patients, despite severe early vision loss.

ModelVariant: The mouse model disrupts the expression of the endogenous GC1 protein product but does not feature knock-in of a variant from a human patient.

ExperimentName: Updated phenotypes from homozygous Gucy2e mouse knockout model

NonHumanModel: Mus musculus

GeneAlteration: The mouse Gucy2e gene was disrupted by the introduction of a neomycin-resistance gene cassette into exon 5, resulting in a truncated protein lacking its transmembrane domain (PMID: 10407028). The effects of this knockout were studied in both heterozygous and homozygous states.

ModelPhenotype: HP:0030465 (Undetectable light-adapted electroretinogram), HP:0030483 (Reduced amplitude of dark-adapted bright flash electroretinogram a-wave), HP:0030469 (Abnormal dark-adapted electroretinogram), HP:0000479 (Abnormal retinal morphology)

HumanPhenotype: HP:0007663 (Reduced visual acuity), HP:0007688 (Undetectable light- and dark-adapted electroretinogram), HP:0007703 (Abnormality of retinal pigmentation)

ModelEvidence: This publication confirms previously-reported ERG abnormalities of rod and especially cone photoreceptors. The abnormal retinal morphology HPO term refers to abnormalities in the ultrastructure of the photoreceptor outer segment, which exhibited disorganization (Figures S2B, S2F, 8C, and 8E) and low GCAP1 and GCAP2 expression levels (Figures 5J and 5N), providing early signs of instability and degeneration.

ModelVariant: The mouse model disrupts the expression of the endogenous GC1 protein product but does not feature knock-in of a variant from a human patient.

ExperimentName: This macaque model harbors a homozygous loss-of-function variant in PDE6C.

NonHumanModel: Macaca mulatta

GeneAlteration: The model animals are homozygous for a missense variant, p.Arg565Gln, which is shown to cause a decrease in enzymatic activity.

ModelPhenotype: HP:0007663 (Reduced visual acuity, particularly in well illuminated settings where unaffected animals led them by the hand), HP:0001483 (Eye poking), HP:0030465 (Undetectable light-adapted electroretinogram), normal dark-adapted ERG, HP:0007401 (Macular atrophy), HP:0011504 (Bull's eye maculopathy), HP:0030619 (Reduced OCT-measured foveal thickness), HP:0030610 (Photoreceptor outer segment loss on macular OCT), HP:0030609 (Photoreceptor layer loss on macular OCT)

HumanPhenotype: HP:0030465 (Undetectable light-adapted electroretinogram), HP:0030534 (Abnormal best corrected visual acuity test), HP:0000551 (Color vision defect), HP:0000613 (Photophobia), HP:0000639 (Nystagmus), HP:0007401 (Macular atrophy), HP:0000545 (Myopia)

ModelEvidence: This is a naturally occurring macaque model that matches the autosomal recessive mode of inheritance from the human patients (Figure 7) and exhibits reduced visual acuity (Supplemental Video 1), lack of light-adapted ERG responses and normal dark-adapted ERG responses (Figures 1A-1E, Figure 2). The affected animals also exhibit progressive macular atrophy consistent with achromatopsia (Figure 3). Reduced foveal thickness was also observed (Figures 4A, 4B), as well as thinning of the outer nuclear layer and photoreceptor outer segments (Figures 5A, 5B).

ModelVariant: This model did not introduce a disease-associated variant known from an affected human patient, but rather studied a naturally occurring variant disrupting the PDE6C locus.

ExperimentName: CRISPR/Cas9-based disruption of mouse Impg2

NonHumanModel: Mus musculus

GeneAlteration: Model animals were subjected to CRISPR/Cas9-based deletion of 7bp from exon 3 of Impg2, and analyzed in the homozygous state. Absence of Impg2 signal was confirmed by immunofluorescent staining. Mice were studied at ages 5 months and 8 months.

ModelPhenotype: HP:0030612 (Abnormal retinal morphology, specifically mislocalization / scattering of IMPG1 throughout the outer segment and at the boundary with the RPE), HP:0030643 (Vitelliform-like subretinal lesions), HP:0000654 (Decreased light- and dark-adapted electroretinogram amplitude)

HumanPhenotype: HP:0000529 (Progressive visual loss), HP:0000662 (Nyctalopia), HP:0000551 (Color vision defect), HP:0008002 (Abnormality of macular pigmentation), HP:0000543 (Optic disc pallor), HP:0007843 (Attenuation of retinal blood vessels), HP:0000533 (Chorioretinal atrophy), HP:0000518 (Cataract), HP:0008323 (Abnormal light- and dark-adapted electroretinogram), HP:0007737 (Bone spicule pigmentation of the retina), HP:0007994 (Peripheral visual field loss), HP:0000603 (Central scotoma)

ModelEvidence: This is the first mouse model of Impg2 disruption, with confirmed absence of Impg2 in the homozygous animals. Abnormalities included mislocalization of Impg1 and the cone-specific marker Pna (Figure 2), accumulation of anomalous material between the photoreceptor outer segment and RPE (Figure 3), development of subretinal hyper-reflective vitelliform lesions (Figure 4), and reduction in the amplitudes of ERG responses from both rods (Figure 5A) and cones (Figure 5B).

ModelVariant: The model does not introduce a variant previously observed in human patients, but rather disrupts the expression of the Impg2 ortholog.

ExperimentName: CRISPR/Cas9-based disruption of mouse Impg1

NonHumanModel: Mus musculus

GeneAlteration: Model animals were subjected to CRISPR/Cas9-based deletion of 10bp from exon 2 of Impg1, and analyzed in the homozygous state. Absence of Impg1 signal was confirmed by immunofluorescent staining. Mice were studied at ages 5 months and 8 months.

ModelPhenotype: HP:0030612 (Abnormal retinal morphology, specifically mislocalization of chondroitin sulfate in the IPM, with none in the outer segment and more in the inner segment)

HumanPhenotype: HP:0007754 (Macular dystrophy), HP:0007769 (Peripheral retinal degeneration), HP:0032037 (Mildly reduced visual acuity, progressive), HP:0008179 (Decreased Arden ratio of electrooculogram)

ModelEvidence: This is the first mouse model of Impg1 disruption, with confirmed absence of Impg1 in the homozygous animals. The only observed abnormality is mislocalization of chondroitin sulfate in the IPM, with none in the outer segment and more in the inner segment (Figure 7). A mild disruption was observed in the localization of PNA, a cone-specific marker, to the outer segment (Fig. 2F). Impg2 appears to be normally localized (Figure 2C). ERG responses were normal (data not shown). Please note that an independent study generating a different model of homozygous Impg1 disruption reported different findings (PMID: 36140676).

ModelVariant: The model does not introduce a variant previously observed in human patients, but rather disrupts the expression of the Impg1 ortholog.

ExperimentName: Colorblind squirrel monkeys were rescued by human OPN1LW.

NonHumanModel: Saimiri sciureus

GeneAlteration: Male squirrel monkeys were missing OPN1LW gene. Controls with the intact gene were not part of the study.

RescueVariant: Rescue was performed by subretinal injection of recombinant adeno-associated virus containing human OPN1LW under control of the appropriate enhancer and promoter and featured the wild-type gene rather than a variant.

RescuePhenotype: The rescued phenotypes are inability to discriminate between blue and green wavelengths to obtain a food reward and defects in performance on a computer-administered Cambridge colour test.

RescueMethod: This rescue model has injection of recombinant adeno-associated virus containing human wild-type OPN1LW under control of the appropriate enhancer and promoter.

RescueEvidence: Squirrel monkeys gained the ability to discriminate between blue and green wavelengths to obtain a food reward (data not shown), as well as significant improvement in ability to distinguish colors occurring at ~20 weeks post-injection (Figure 3A). Gaps in the ability to detect certain wavelengths pre-injection (solid lines) were filled in post-injection (dotted lines) in monkey 1 (Panel 3B) and monkey 2 (Panel 3C). These confirmed that monkeys had become trichomatic and matched the new ability to access food rewards.

ModelVariant: The model does not include any human OPN1LW variant, only the wild-type gene.

ExperimentName: Transgenic mouse expressing human GUCY2D R838S

NonHumanModel: Mus musculus

GeneAlteration: A human GUCY2D transgene encoding the R838S substitution was placed under the control of the rod opsin promoter and injected into mouse eggs, creating a mouse model with rod-specific expression of the variant (and only inefficient expression in cones).

ModelPhenotype: HP:0030469 (Abnormal dark-adapted electroretinogram), HP:0030483 (Reduced amplitude of dark-adapted bright flash electroretinogram a-wave), HP:0030478 (Abnormal amplitude of dark-adapted bright flash electroretinogram), HP:0030609 (Photoreceptor layer loss on macular OCT), HP:0410280 (Pediatric onset), HP:0000546 (Retinal degeneration)

HumanPhenotype: HP:0000548 (Cone/cone-rod dystrophy), HP:0007663 (Reduced visual acuity), HP:0007994 (Peripheral visual field loss), HP:0000613 (Photophobia), HP:0011504 (Bull's eye maculopathy), HP:0030465 (Undetectable light-adapted electroretinogram), HP:0030469 (Abnormal dark-adapted electroretinogram)

ModelEvidence: The model system approximately recapitulates the mode of inheritance (autosomal dominant) of the human disease state. At the molecular level, it increases the sensitivity of cGMP synthesis to calcium ion concentration (Figures 2B, 7A). At the ocular level, rod response (dark-adapted ERG) amplitudes were diminished starting at one month of age (Figure 4A, 4B), particularly by 6 months (Figure 5A, 5B), while cones lacking transgene expression remained functional (Figure 5A, 5C). Retinal morphology between 3 and 5 months of age showed outer nuclear layer reduction (Figures 6A, 7C) linked to photoreceptor loss (Figures 6B, 7D).

ModelVariant: NM_000180.4(GUCY2D):c.2512C>A (p.Arg838Ser) (ClinVar: 98568)

ExperimentName: Genotyping of 4 Australian Cattle Dogs affected with NCL

NonHumanModel: Canis familiaris

GeneAlteration: While the model does not have an engineered gene alteration, all four affected animals are homozygous for the CLN5:c.619C>T variant. The unaffected parents of a fifth affected dog were both heterozygotes for this variant.

ModelPhenotype: HP:0001250 (Seizure), HP:0000572 (Visual loss), HP:0000708 (Behavioral abnormality), HP:0002370 (Poor coordination), HP:0002312 (Clumsiness), HP:0001251 (Ataxia), HP:0100299 (Muscle fiber inclusion bodies), HP:0002283 (Global brain atrophy), HP:0002119 (Ventriculomegaly), Note: inclusion bodies are membrane-associated and autofluorescent. Onset of phenotypes was between 12-18 months, and the condition was rapidly progressive, with euthanasia occurring between 20-27 months of age.

HumanPhenotype: HP:0003208 (Fingerprint intracellular accumulation of autofluorescent lipopigment storage material), HP:0011463 (Childhood onset), HP:0001268 (Mental deterioration), HP:0000572 (Visual loss), HP:0001251 (Ataxia), HP:0002540 (Inability to walk), HP:0001250 (Seizure), HP:0100952 (Enlarged sylvian cistern), HP:0002059 (Cerebral atrophy), HP:0001272 (Cerebellar atrophy)

ModelEvidence: The model phenotypes closely match the human patient phenotypes in the timing of onset and rapid progression (Table 3), neurological details, vision problems, loss of coordination, and microscopic accumulation of storage/inclusion bodies (Figure 4, Figure 5).

ModelVariant: CLN5:c.619C>T p.Gln207Ter

ExperimentName: Recombinase-based variant knock-in to the mouse Rpe65 locus

NonHumanModel: Mus musculus

GeneAlteration: A substitution equivalent to the human NM_000329.3(RPE65):c.1430A>G (p.Asp477Gly) variant was knocked into the mouse Rpe65 locus by Flp-recombinase, which allowed the selection cassette to be subsequently excised.

ModelPhenotype: HP:0030602 (Abnormal fundus autofluorescence imaging), HP:0030329 (Retinal thinning), HP:0030483 (Reduced amplitude of dark-adapted bright flash electroretinogram a-wave), HP:0008275 (Abnormal light-adapted electroretinogram)

HumanPhenotype: HP:0000662 (Nyctalopia), HP:0007688 (Undetectable light- and dark-adapted electroretinogram), HP:0001098 (Abnormal fundus morphology), HP:0000529 (Progressive visual loss)

ModelEvidence: The mice exhibit reduced levels of RPE65 protein (Figure 3A) and enhanced ubiquitination (Figure 3B), indicating higher susceptibility to proteolysis. Despite normal 11-cis retinal levels (Figure 7C), the heterozygous knock-in animals exhibit abnormal accumulation of retinyl esters (Figure 7B), recapitulating a key molecular defect of the human patients. Photobleaching revealed defects in regeneration of 11-cis-retinal (Figure 7F) and accumulation of retinyl esters (Figure 7G). These defects were observable in both the heterozygous knock-in (mild) and homozygous knock-in (more severe). Accumulation of autofluorescent spots in the fundus (Figure 4), progressive thinning of the outer nuclear layer (Figure 5), and abnormal ERG responses (Figure 6) were seen in heterozygous knock-in and especially homozygous knock-in mice with age. Similar phenotypic results were observed with a third, similar knock-in mouse model (PMID: 28041994).

ModelVariant: The model knocks the NM_000329.3(RPE65):c.1430A>G (p.Asp477Gly) variant (ClinVar:750796) into the endogenous mouse Rpe65 locus.

ExperimentName: CRISPR/Cas9-based disruption of mouse Impg2

NonHumanModel: Mus musculus

GeneAlteration: Model animals were subjected to CRISPR/Cas9-based deletion of 166bp from exon 2 of Impg2, and analyzed in the homozygous state. Absence of Impg2 signal was confirmed by RT-PCR. Mice were studied at ages 3, 6, and 13 months.

ModelPhenotype: HP:0000654 (Decreased light- and dark-adapted electroretinogram amplitude), HP:0000580 (Pigmentary retinopathy), HP:0030609 (Photoreceptor layer loss on macular OCT)

HumanPhenotype: HP:0000529 (Progressive visual loss), HP:0000662 (Nyctalopia), HP:0000551 (Color vision defect), HP:0008002 (Abnormality of macular pigmentation), HP:0000543 (Optic disc pallor), HP:0007843 (Attenuation of retinal blood vessels), HP:0000533 (Chorioretinal atrophy), HP:0000518 (Cataract), HP:0008323 (Abnormal light- and dark-adapted electroretinogram), HP:0007737 (Bone spicule pigmentation of the retina), HP:0007994 (Peripheral visual field loss), HP:0000603 (Central scotoma)

ModelEvidence: Abnormalities of the homozygous Impg2 deletion mice included reduction in the amplitudes of ERG responses from both rods and cones at age 6 months (Figure 2). Pigmentary retinopathy was also observed (Figure 2C), as well as progressive photoreceptor layer loss (Figure 3). Cone markers such as PNA and M-opsin were mislocalized (Figure 4), indicating cone cell disorganization. Enhanced apoptosis was also observed in the photoreceptor cell segments (Figure 5), consistent with the decreased outer nuclei layer thickness.

ModelVariant: The model does not introduce a variant previously observed in human patients, but rather disrupts the expression of the Impg2 ortholog.

ExperimentName: Phenotypic characterization of the heterozygous Timp3Ser179Cys Knock-In Mouse

NonHumanModel: Mus musculus (129/Sv and hybrid C57BL/6 × 129/SvJ background)

GeneAlteration: The mouse Timp3 ortholog was subjected to site-directed mutagenesis to introduce a change equivalent to the human variant encoding the Ser179Cys substitution associated with Sorsby Fundus Dystrophy (PMID:8634721). This variant was introduced into embryonic stem cells by homologous recombination, generating animals for germline transmission of the Timp3Ser179Cys knock-in allele of interest.

ModelPhenotype: HP:0007703 (Abnormality of retinal pigmentation), Abnormalities of the inner aspect of Bruch's membrane

HumanPhenotype: HP:0007703 (Abnormality of retinal pigmentation, PMID:27601084, PMID:16989765), thickening of the inner part of Bruch's membrane

ModelEvidence: While the model system phenotype does not recapitulate all of the human SFD phenotypes, most of which represent the later stages of disease progression, it does recapitulate some early events from the human phenotype, such as abnormalities of Bruch's membrane and the retinal pigment epithelium. The retinal pigment epithelium exhibits structural abnormalities in mutant animals relative to wild-type controls, at both 8 months and 30 months. At 8 months specifically, 15%–20% of RPE areas analyzed showed loss of vertical orientation and increased distances between processes at the cellular bases (Fig. 3) . Patchy thinning of basal microvilli was observed adjacent to Bruch’s membrane, with disrupted packing of microvilli and caverns extending from the basal labyrinth (Figure 3). Timp3 western blots of RPE-choroid ECM extracts from knock-in mice also accumulated higher-molecular weight complexes of Timp3 (Figure 5), similar to the exogenously expressed human variant (PMID:10854443).

ModelVariant: The model variant is a knock-in modification to the mouse Timp3 ortholog that is equivalent to the human NM_000362.5(TIMP3):c.536C>G, (p.Ser179Cys) missense variant (ClinVar:12678). While the article refers to the variant as "Ser156Cys", the updated nomenclature should be Ser179Cys (including the 23-amino acid N-terminal signal peptide).

ExperimentName: Morpholino-based knockdown of zbbs1 disrupts ciliary beating pattern.

NonHumanModel: Danio rerio

GeneAlteration: The model animals have been subjected to morpholino-based knockdown of zbbs1, the zebrafish ortholog of human BBS1.

ModelPhenotype: HP:0012262 (Abnormal ciliary motility), HP:0000107 (Renal cyst)

HumanPhenotype: HP:0000639 (Nystagmus), HP:0000510 (Rod-cone dystrophy), HP:0007663 (Reduced visual acuity), HP:0000662 (Nyctalopia), HP:0000518 (Cataract), HP:0008323 (Abnormal light- and dark-adapted electroretinogram), HP:0000107 (Renal cyst), HP:0001513 (Obesity), HP:0010442 (Polydactyly), HP:0002463 (Language impairment), HP:0000026 (Male hypogonadism)

ModelEvidence: Morpholino-based knockdown of the zbbs1 gene causes hydrocephalus (Figure 3B), formation of pronephritic cysts (Figure 3G), embyronic body axis abnormalities (Figure 4B), heart looping defects (Figure 5B), longer cilia (Figure 7F), and normal ciliary ultrastructure (Figure 7I), and aberrant ciliary motility in the pronephritic tubule and nasal pit (Supplementary Movies).

ModelVariant: This model did not introduce a disease-associated variant known from an affected human patient, but rather studied the effects of silencing the gene product.

ExperimentName: Conditional Kcnj13 knockout in mice

NonHumanModel: Mus musculus

GeneAlteration: Conditional knockout was generated by inserting a cassette into exon 2 of 3 in the presence of Cre driven by the VMD2 (RPE-specific) promoter.

ModelPhenotype: Photoreceptor layer loss on macular OCT HP:0030609, Retinal degeneration HP:0000546, Abnormality of retinal pigmentation HP:0007703, Attenuation of retinal blood vessels HP:0007843, Decreased light- and dark-adapted electroretinogram amplitude HP:0000654

HumanPhenotype: Reduced visual acuity HP:0007663, Constriction of peripheral visual field HP:00011, Infantile onset HP:0003593, Strabismus HP:0000486, Nystagmus HP:0000639, Progressive night blindness HP:0007675, Moderate myopia HP:0031624, Decreased light- and dark-adapted electroretinogram amplitude HP:0000654, Presenile cataracts HP:0007819, Nummular pigmentation of the fundus HP:0030505, Retinal pigment epithelial loss on macular OCT HP:0030611

ModelEvidence: The 6-month-old mouse with induced Cre recombinase shows loss of photoreceptor cell layers (Figure 4F) and severe retinal degeneration (Figure 4G) relative to the control lacking Cre (Figure 4E), but with relative preservation of retinal morphology near the optic nerve. The RPE layer in the Cre-positive knockout cells shows irregular and flattened cell shapes with abnormal nuclear and cytoskeletal morphology relative to the control (Figure 5D). The knockout mouse fundus shows distinct inclusions, especially in the outer segment, as well as some attenuation of retinal blood vessels (Figure 6). ERG a-waves and b-waves are also extinguished (Figure 7A), consistent with loss of the entire photoreceptor layer (Figures 4F, 5B). There was also low amplitude of c-waves originating from the RPE cells (Figure 7C) that could be restored by lentiviral transduction of the functional KCNJ13 gene (Figures 7C, 7D).

ModelVariant: The model features knockout of the endogenous mouse Kcnj13 rather than knock-in of a mutation equivalent to a variant from a human patient.

ExperimentName: The Nr2e3rd7/rd7 mouse has aberrant proliferation of mitotic progenitors caused by aberrant expression of rod-specific and cone-specific genes such as blue opsin, resulting from failure to suppress the cone generation program and resulting aberrant expression of rod-specific and cone-specific genes.

NonHumanModel: Mus musculus

GeneAlteration: The Rd7 mouse model has been previously described in PMID: 10805811 and PMID: 11487564, and harbors a large out-of-frame deletion within the Nr2e3 locus in the homozygous state.

ModelPhenotype: Abnormal retinal morphology on macular (whorls and rosettes in outer nuclear layer) OCT HP:0030612, Retinal degeneration (late onset) HP:0000546, Retinal thinning HP:0030329

HumanPhenotype: Retinal degeneration HP:0000546, Sensory hypersensitivity (enhanced blue cone sensitivity) HP:5200058

ModelEvidence: The model has been previously published and exhibits ~30x enhanced blue cone sensitivity (PMID: 11487564), retinal spotting throughout the fundus including whorls in the outer nuclear layer (PMID: 11487564), and late onset retinal degeneration characterized by non-apoptotic cell death reduction of outer nuclear layer thickness (PMID: 34561487), and over-proliferation of ectopic retinal progenitors (PMID: 17266784), as well as increased expression of cone-associated genes (Figure 1).

ModelVariant: The model harbors a deletion of 380bp spanning intronic and coding regions, rather than a specific variant from a human patient.

ExperimentName: Naturally occurring mouse model of Nyx loss-of-function

NonHumanModel: Mus musculus

GeneAlteration: This naturally occurring model, previously known to exhibit the absence of b-wave in ERG recordings, harbors an 85-bp deletion in the final exon of the Nyx gene that shifts the frame and replaces the C-terminal 61% of the protein product with 170 novel amino acids. The predicted effect is loss-of-function.

ModelPhenotype: HP:0007984 (Electronegative electroretinogram), HP:0000649 (Abnormality of visual evoked potentials), HP:0007663 (Reduced visual acuity), HP:0001419 (X-linked recessive inheritance)

HumanPhenotype: HP:0030640 (Complete congenital stationary night blindness), HP:0030469 (Abnormal dark-adapted electroretinogram), HP:0007642 (Congenital stationary night blindness), HP:0007663 (Reduced visual acuity), HP:0031624 (Moderate myopia), HP:0007984 (Electronegative electroretinogram)

ModelEvidence: The model exhibited reduced amplitude of dark-adapted bright flash electroretinogram b-wave (electronegative ERG) but normal amplitude of the a-wave (PMID: 9804152). Visually-driven cortical activity was also abnormal (9804152). Visual acuity was also reduced (Figure 4). Inheritance was X-linked recessive (Figure 3), which also matches the human families.

ModelVariant: The model is naturally occurring, and so the affected animals harbor a variant that does not have an exact human patient equivalent.

NonHumanModel Mus musculus

GeneAlteration oligonucleotide-directed mutagenesis of lambda phage to make a p.T494M vector to inject mice.

ModelPhenotype HP:0031531

HumanPhenotype HP:0000572

ModelEvidence Electron microscopy of retina showed degeneration of RPE indicated by abnormal basal morphology (fig. 5)

ModelVariant NM_004698.3(PRPF3):c.1481C>T (p.Thr494Met), 3352

ExperimentName: "Variant overexpression in zebrafish causes defects in visual function."

NonHumanModel: Danio rerio

GeneAlteration: The model animals have been subjected to microinjection of PRPF4 mRNA (either wild-type or harboring the p.Pro315Leu variant), with expression levels comparable to the endogenous gene.

ModelPhenotype: Photoreceptor layer loss on macular OCT HP:0030609, Inner retinal layer loss on macular OCT HP:0030620, Photoreceptor outer segment loss on macular OCT HP:0030610

HumanPhenotype: Constriction of peripheral visual field HP:0001133, Reduced visual acuity HP:0007663,, Decreased light- and dark-adapted electroretinogram amplitude HP:0000654. Retinal degeneration HP:0000546, Macular degeneration HP:0000608, Optic disc pallor HP:0000543, Attenuation of retinal blood vessels HP:0007843, Pigmentary retinopathy HP:0000580

ModelEvidence: The variant causes severely disrupted photoreceptors in the retina (Figure 5D), reduced rhodopsin staining (rod marker) in the IS/OS layer (Figures 5E-5J) and other deformities such as malformed brains, short trunks, cardiac edema and curved body axis, at higher levels than in the wild-type control (Figures 5B and 5C). The retinal transcripts opn1lw1, gnat2, rs1, snrpg, prph2b, gnb3, and rho were decreased in the variant-expressing zebrafish (Figure 5K), while the splicing factor transcripts prpf4, prpf3, prpf31, prpf6, prpf8, snrnp200, eftud2, and sart1 were increased (Figures 5A, 5L).

ModelVariant: This model introduced the disease-associated variant NM_001244926.2(PRPF4):c.941C>T (p.Pro314Leu) in the heterozygous state (ClinVar ID: 143057).

ExperimentName: The rds mouse harbors loss-of-function variants in the Prph2 gene.

NonHumanModel: Mus musculus

GeneAlteration: The model animals are homozygous for a loss-of-function variant in the Prph2 locus known as retinal degeneration slow (rds). The causal variant appears to encode a p.Gln340Pro missense change that results in the inability to detect the Prph2 protein by antibody.

ModelPhenotype: HP:0000546 (Retinal degeneration), HP:0030610 (Photoreceptor outer segment loss on macular OCT)

HumanPhenotype: HP:0030643 (Vitelliform-like retinal lesions), HP:0000533 (Chorioretinal atrophy), HP:0001105 (Retinal atrophy), HP:0007663 (Reduced visual acuity), HP:0000580 (Pigmentary retinopathy), HP:0030469 (Abnormal dark-adapted electroretinogram), HP:0008275 (Abnormal light-adapted electroretinogram), HP:0007843 (Attenuation of retinal blood vessels), HP:0011506 (Choroidal neovascularization), HP:0030499 (Macular drusen)

ModelEvidence: This is a naturally occurring mouse model with homozygous disruption of the Prph2 locus. Phenotypes include progressive degeneration of retina, absence of rods at age 7-10 months, and reduction of the number of rows of photosensitive cell nuclei to only 1-4 rows (described in previous publications PMID: 705766 and PMID: 419532). Other previous publications have reported that the mice exhibit abnormal development of photoreceptor outer segments, as well as subsequent gradual photoreceptor degeneration of photoreceptors that is complete by age 1 year (PMID: 2918924).

ModelVariant: This model did not introduce a disease-associated variant known from an affected human patient, but rather studied a naturally occurring p.Gln340Pro missense variant disrupting the Prph2 locus.

ExperimentName: Oxidative stress sensitivity in the homozygous Timp3Ser179Cys Knock-In Mouse

NonHumanModel: Mus musculus (C57Bl/6J background)

GeneAlteration: The gene alteration was constructed in a previous paper (PMID:12147610), in which the mouse Timp3 ortholog was subjected to site-directed mutagenesis to introduce a change equivalent to the human variant encoding the Ser179Cys substitution associated with Sorsby Fundus Dystrophy (PMID:8634721). This variant was introduced into embryonic stem cells by homologous recombination, generating animals for germline transmission of the Timp3Ser179Cys knock-in allele of interest.

ModelPhenotype: HP:0000580 (Pigmentary retinopathy), HP:0007703 (Abnormality of retinal pigmentation)

HumanPhenotype: HP:0007703 (Abnormality of retinal pigmentation)

ModelEvidence: The phenotypes of this model system recapitulate some of the degenerative features of the human model. Sensitivity to oxidative stress was revealed when low-dose sodium iodate triggered RPE degeneration and disorganization in the Timp3 S179C/S179C mice but not the wild-type controls (Figure 4). Rhodamine-phalloidin staining also exhibited an increased area of degeneration in the central region of the RPE in mutant mice but not in the wild-type controls (Figure 5). It is important to point out the caveat that the mice were homozygous for Timp3 Ser179Cys, whereas human patients are heterozygous. This difference in genotype introduces the possibility of loss-of-function effects that are specific to the mouse but absent from the human patients.

ModelVariant: The model variant is a knock-in modification to the mouse Timp3 ortholog that is equivalent to the human NM_000362.5(TIMP3):c.536C>G, (p.Ser179Cys) missense variant (ClinVar:12678).

ExperimentName: Phenotypic characterization of the homozygous Timp3-/- Knock-Out Mouse

NonHumanModel: Mus musculus (C57/Bl6 or CD1 background)

GeneAlteration: A neomycin resistance expression cassette was cloned into plasmid-borne exon 3 of mouse Timp3. The linearized construct was transfected into embryonic stem cells and injected into blastocysts. Animals that had undergone homologous recombination were identified by locus-specific genomic PCR reactions. Predicted loss of Timp3 due to a premature stop codon and nonfunctional mRNA was confirmed at the protein level.

ModelPhenotype: HP:0030605 (Abnormal indocyanine green angiography), HP:0025568 (Abnormal morphology of the choroidal vasculature), HP:0030979 (Dilatation of large choroidal vessels)

HumanPhenotype: HP:0011506 (Choroidal neovascularization)

ModelEvidence: The model showed dilatation of the large choroid vessels, which appeared large and hyperfluorescent during ICG angiography, with balloon-like spots (Figure 3A-3B). While wild-type controls exhibited normal choroidal blood vessel network, Timp3-/- animals had abnormal vessel formations that were strongly dilated or fused (Figures 3C-3H). During in situ zymography, higher local fluorescence intensity indicated increased MMP2 and MMP9 activity in the knockout animals, as expected. Aortic explants from knockout mice showed higher spontaneous microvessel outgrowth than their counterparts from wild-type mice (Figure 6). Rescue assays suggest that the antiangiogenic activity requires the C-terminal region of TIMP3 (Figure 7).

ModelVariant: N/A (Timp3 knockout)

ExperimentName: Horse model of TRPM1 loss-of-function

NonHumanModel: Equus ferus caballus

GeneAlteration: The horse has homozygous disruption of the TRPM1 gene by a naturally occurring insertion of a 1378 bp transposon in intron 1 (g. 108,297,929_108,297,930 ins1378). A previous publication by the same group has shown that TRPM1 expression is absent from the skin and retina of these horses (PMID: 18660533).

ModelPhenotype: HP:0001053 (Hypopigmented skin patches), HP:0000591 (Abnormal sclera morphology), HP:0000662 (Nyctalopia), HP:0007984 (Electronegative electroretinogram),

HumanPhenotype: HP:0000662 (Nyctalopia), HP:0000545 (Myopia), HP:0000572 (Visual loss), HP:0007984 (Electronegative electroretinogram), HP:0000958 (Dry skin), HP:0000964 (Eczema)

ModelEvidence: The affected horses exhibit night blindness and abnormal dark-adapted ERG with absent b-wave and increased amplitude of a-wave (Figure 1). Both phenotypes are similar to the affected human patients. Melanocyte dysfunction is also shown by unpigmented areas of the skin (Figures 1 and 2) and the sclera of the eye (Figure 2A). These pigment phenotypes do not have a human equivalent, although some affected patients have been reported to have dry skin or a history of eczema (PMID: 19878917).

ModelVariant: The model harbors a naturally occurring variant that does not have an equivalent / orthologous variant reported in human patients.

ExperimentName: Mouse model of Adam9 loss-of-function

NonHumanModel: Mus musculus

GeneAlteration: The mice harbor homozygous knockout of the Adam9 gene by an insertion of a neomycin selection cassette in to the exon encoding amino acids 32 to 66 of Adam9 (PMID: 11839819).

ModelPhenotype: HP:0000546 (Retinal degeneration), HP:0007703 (Abnormality of retinal pigmentation), HP:0030610 (Photoreceptor outer segment loss on macular OCT), HP:0030483 (Reduced amplitude of dark-adapted bright flash electroretinogram a-wave), HP:0007984 (Electronegative electroretinogram), HP:0008323 (Abnormal light- and dark-adapted electroretinogram)

HumanPhenotype: HP:0410280 (Pediatric onset), HP:0007663 (Reduced visual acuity), HP:0007401 (Macular atrophy), HP:0000580 (Pigmentary retinopathy), HP:0007769 (Peripheral retinal degeneration), HP:0008323 (Abnormal light- and dark-adapted electroretinogram), HP:0000548 (Cone/cone-rod dystrophy), HP:0007994 (Peripheral visual field loss), HP:0000545 (Myopia)

ModelEvidence: The affected mice exhibit an abnormal gap between the RPE and the photoreceptor outer segment, which would normally be in contact (Figure 5B). The gap contains macrophages (Figure 5L). Outer nuclear layer thinning is observed (Figure 5D), as well as material deposited between the RPE and Bruch's membrane, which may be analogous to drusen deposits in humans (Figure 5K). These findings collectively show an adhesion defect at the interface between the photoreceptor outer segment and the RPE. This evidence of retinal degeneration was complemented by abnormalities in both rod- and cone-driven ERG responses (Figure 4), matching a feature of the human patients.

ModelVariant: The model harbors a targeted disruption that does not have an equivalent / orthologous variant reported in human patients.

ExperimentName: Variant knock-in to the mouse Rpe65 locus triggers aberrant mRNA splicing.

NonHumanModel: Mus musculus

GeneAlteration: A substitution equivalent to the human NM_000329.3(RPE65):c.1430A>G (p.Asp477Gly) variant was knocked into the mouse Rpe65 locus by CRISPR/Cas9-based editing.

ModelPhenotype: HP:0000479 (Abnormal retinal morphology), HP:0030469 (Abnormal dark-adapted electroretinogram), HP:0030483 (Reduced amplitude of dark-adapted bright flash electroretinogram a-wave), Retinal thinning HP:0030329

HumanPhenotype: HP:0000662 (Nyctalopia), HP:0007688 (Undetectable light- and dark-adapted electroretinogram), HP:0001098 (Abnormal fundus morphology), HP:0000529 (Progressive visual loss)

ModelEvidence: Despite normal 11-cis retinal levels (Figure 3E), the heterozygous knock-in animals exhibit abnormal accumulation of retinyl esters (Figure 3F), recapitulating a key molecular defect of the human patients. The homozygous (but not heterozygous) knock-in animals also exhibit vacuole formation in the outer segment adjacent to the retinal pigment epithelium (Figure 3B) and abnormalities on dark-adapted ERG indicative of slower recovery of rod function (Figures 4A, 4B) and cone function (Figure 5D) as well as reduced retinal thickness (Figure 5A) after long-term chronic visual pigment bleaching.

ModelVariant: The model knocks the NM_000329.3(RPE65):c.1430A>G (p.Asp477Gly) variant (ClinVar:750796) into the mouse Rpe65 locus.

ExperimentName: Knockin of the p.Tyr141Cys variant into mouse Prph2 results in retinal defects.

NonHumanModel: Mus musculus

GeneAlteration: The model animals are heterozygous for knock-in of the p.Tyr141Cys variant into the Prph2 locus.

ModelPhenotype: HP:0030469 (Abnormal dark-adapted electroretinogram), HP:0000546 (Retinal degeneration), HP:0030610 (Photoreceptor outer segment loss on macular OCT), HP:0012045 (Retinal flecks)

HumanPhenotype: HP:0030643 (Vitelliform-like retinal lesions), HP:0000533 (Chorioretinal atrophy), HP:0001105 (Retinal atrophy), HP:0007663 (Reduced visual acuity), HP:0000580 (Pigmentary retinopathy), HP:0030469 (Abnormal dark-adapted electroretinogram), HP:0008275 (Abnormal light-adapted electroretinogram), HP:0007843 (Attenuation of retinal blood vessels), HP:0011506 (Choroidal neovascularization), HP:0030499 (Macular drusen)

ModelEvidence: This knock-in mouse model has normal expression and localization of Prph2 (Fig. 1), but exhibits phenotypes including photoreceptor outer segment loss (Fig. 2), decreased rod ERG (Fig. 3A), and photoreceptor layer degeneration (Fig. 4). Homozygous mice showed decreased cone ERG as well (Figs. 3B, 3C). Yellow retinal flecks were observed in the fundus (Fig. 5). Abnormal high molecular weight complexes containing Prph2 were also observed in western blotting, along with the absence of normal monomers and dimers in the homozygous animals (Figs. 6 and 7).

ModelVariant: This mouse model has introduced a disease-associated variant known from an affected human patient, NM_000322.5(PRPH2):c.422A>G (p.Tyr141Cys), ClinVar ID: 98666.

Zebrafish harboring an engineered mutation in the prpf4 gene exhibit enhanced brain and spinal cord apoptosis. The mechanism is loss-of-function. Matches the patients?

ExperimentName: Phenotypes from homozygous Gucy2e mouse knockout model

NonHumanModel: Mus musculus

GeneAlteration: The mouse Gucy2e gene was disrupted by the introduction of a neomycin-resistance gene cassette into exon 5, resulting in a truncated protein lacking its transmembrane domain (PMID: 10407028). The effects of this knockout were studied in both heterozygous and homozygous states.

ModelPhenotype: HP:0030469 (Abnormal dark-adapted electroretinogram), HP:0030465 (Undetectable light-adapted electroretinogram), HP:0008020 (Cone dystrophy)

HumanPhenotype: HP:0007663 (Reduced visual acuity), HP:0007688 (Undetectable light- and dark-adapted electroretinogram), HP:0007703 (Abnormality of retinal pigmentation)

ModelEvidence: By 5 weeks of age, Gucy2e-deficient animals exhibit dramatic reduction/degeneration of cones in the outer nuclear layer (Fig. 3a–d). This was confirmed by disappearance of labeling of cone cell nuclei by the lectin PNA (Fig. 3g-h). ERG showed that rod a-wave and b-wave were markedly reduced by 1 month of age, while cone responses were nondetectable as early as 2 months of age (Fig. 4a-b). A proposed explanation for the absence of more severe rod defects is the continued presence of the Gucy2f paralog in this mouse model, which may compensate for the absence of Gucy2e function in rod cells specifically. This hypothesis has been confirmed in a subsequent double-knockout model (PMID: 17255100)

ModelVariant: The mouse model disrupts the expression of the endogenous GC1 protein product but does not feature knock-in of a variant from a human patient.

This article studies mice known as rds with homozygous disruption of the Prph2 locus. Phenotypes include progressive degeneration of retina, absence of rods at age 7-10 months, and reduction of the number of rows of photosensitive cell nuclei to only 1-4 rows. The mouse has been previously published (PMID: 705766).

ExperimentName: Genetically engineered Bbs7 homozygous knockout mouse

NonHumanModel: Mus musculus

GeneAlteration: The model animals harbor a homozygous replacement of Bbs7 exon 5 with a neomycin cassette, resulting in a frameshifted allele confirmed by western blotting to result in a null effect on the gene product.

ModelPhenotype: HP:0000546 (Retinal degeneration), HP:0032558 (Absent sperm flagella), HP:0001513 (Obesity), HP:0002119 (Ventriculomegaly), HP:0003251 (Male infertility), HP:0030609 (Photoreceptor layer loss on macular OCT), HP:0012258 (Abnormal axonemal organization of respiratory motile cilia), HP:0033524 (Abnormal sperm axoneme morphology)

HumanPhenotype: HP:0001956 (Truncal obesity), HP:0000618 (Blindness), HP:0001249 (Intellectual disability), HP:0001631 (Atrial septal defect), HP:0001640 (Cardiomegaly), HP:0100598 (Pulmonary edema), HP:0012584 (Bilateral renal hypoplasia), HP:0004719 (Hyperechogenic kidneys), HP:0003774 (Stage 5 chronic kidney disease), HP:0000580 (Pigmentary retinopathy), HP:0000648 (Optic atrophy), HP:0008043 (Retinal arteriolar constriction), HP:0007737 (Bone spicule pigmentation of the retina), HP:0007754 (Macular dystrophy)

ModelEvidence: This is a genetically engineered mouse model of biallelic Bbs7 disruption. The mutant animals with biallelic Bbs7 disrupion exhibit photoreceptor inner and outer segment loss (Figure 1), ventriculomegaly (Figure 1), reduced number of cilia and shortened cilia in brain tissue (Figure 2), abnormal axonemal structure / microtubule number abnormality in brain cilia (Figures 2F, 2G), lack of sperm flagella (Figure 3), Abnormal sperm axoneme microtubule organization (Figure 3), destabilization /absence of BBS2 in testes (Figure 4), and abnormal accumulation of some ciliary membrane proteins (dopamine D1 receptor, Figure 6) but not others (polycystin-1 or polycystin-2, Figure 5). Kidney cysts and polydactyly were looked for and found to be absent.

ModelVariant: This model did not introduce a disease-associated variant known from an affected human patient, but rather studied a genetically engineered null variant disrupting Bbs7 expression.

ExperimentName: Mouse model of Trpm1 loss-of-function

NonHumanModel: Mus musculus

GeneAlteration: The mouse has homozygous disruption of the Trpm1 gene by targeted deletion of regions from exons 3, 4, and 5 (PMID: 19439586).

ModelPhenotype: HP:0007984 (Electronegative electroretinogram)

HumanPhenotype: HP:0000662 (Nyctalopia), HP:0000545 (Myopia), HP:0000572 (Visual loss), HP:0007984 (Electronegative electroretinogram)

ModelEvidence: The affected mice exhibit abnormal dark-adapted ERG with absent b-wave and normal a-wave (Figure 3), similar to the affected human patients. Retinal slices from these mice exhibit defects in chemically stimulated light responses (Figure 4), indicating that Trpm1 is required for generating the depolarizing light response in ON-bipolar cells.

ModelVariant: The model harbors a targeted deletion that does not have an equivalent / orthologous variant reported in human patients.

ExperimentName: Canine model of PDE6A loss-of-function

NonHumanModel: Canis lupus familiaris

GeneAlteration: Cardigan Welsh Corgi animals were found to develop retinal degeneration due to a homozygous 1-bp deletion variant at codon 616 that results in a frameshift and a premature stop codon (genotype previously reported in PMID: 10393029).

ModelPhenotype: HP:0030474 (Undetectable dark-adapted electroretinogram), HP:0000505 (Visual impairment), HP:0007843 (Attenuation of retinal blood vessels), HP:0030610 (Photoreceptor outer segment loss on macular OCT)

HumanPhenotype: HP:0011463 (Childhood onset), HP:0000662 (Nyctalopia), HP:0007994 (Peripheral visual field loss), HP:0000543 (Optic disc pallor), HP:0007843 (Attenuation of retinal blood vessels), HP:0007737 (Bone spicule pigmentation of the retina), HP:0000654 (Decreased light- and dark-adapted electroretinogram amplitude), HP:0007984 (Electronegative electroretinogram)

ModelEvidence: This mutation caused an Electronegative electroretinogram (HP:0007984) and Abnormal light-adapted electroretinogram (HP:0008275), (Figures 2, 3, and 4). Retinal degeneration (HP:0000546) was observed with outer nuclear photoreceptor layer thinning (HP:0030610, Figure 5). Photoreceptor outer segment loss is visible on macular OCT (Figure 6, Figure 7), particularly loss of rod photoreceptor cells.

ModelVariant: The model does not harbor a variant equivalent to one from the human patients, but rather has a naturally occurring frameshift variant disrupting Pde6a leading to full loss-of-function.

ExperimentName: Rpe65 homozygous knockout triggers loss of cone response in certain mouse models.

NonHumanModel: Mus musculus

GeneAlteration: Rpe65 homozygous knockout was generated by replacing the 5' flanking region and the first three exons of Rpe65 with a PGK-Neo cassette (described in PMID: 9843205).

ModelPhenotype: HP:0008275 (Abnormal light-adapted electroretinogram), HP:0030465 (Undetectable light-adapted electroretinogram)

HumanPhenotype: HP:0030479 (Abnormal amplitude of light-adapted flicker electroretinogram)

ModelEvidence: The human phenotype includes both dark-adapted (rod) and light-adapted (cone) ERG defects. The Rpe65 homozygous knockout mouse model was previously found to have dark-adapted but not light-adapted response defects (PMID: 9843205). This study shows that in mice harboring homozygous knockout of Nrl (homozygous knockout) , Rpe65 homozygous knockout triggers light-adapted (cone) ERG defects as well (Figures 6A and 6B).

ModelVariant: The model disrupts the entire Rpe65 locus rather than introducing a mutation equivalent to a human patient variant.

NonHumanModel: Vervet Monkeys (Chlorocebus pygerythrus)

GeneAlteration: PCR amplification and direct sequencing indicated that all of the vervet monkeys observed and one of the malbrouck monkeys had the TTR Ile122 allele, as opposed to the the other primates (including humans) that harbor the Met122 allele. Other than this variant, the sequence was identical to three other species of monkeys that did not demonstrate amyloidosis phenotypes including 95-98%, 93-94%, and 76-81% amino acid homologies to humans.

ModelPhenotype: HP:0031327, HP:0003216, HP:0011675, HP:0012664 (Transthyretin cardiac amyloidosis, Generalized amyloid deposition, Arrhythmia, Reduced ejection fraction)

ModelFreeText: Haphazardly arranged rigid amyloid fibrils in the heart, Increased cardiothoracic ratio, Increased plasma ANP concentrations

HumanPhenotype: HP:0001627, HP:0011034 (Abnormal heart morphology, Amyloidosis)

HumanFreeText: N/A

ModelEvidence: Aged vervet monkeys were investigated for a naturally-occuring spontaneous systemic amyloidosis and accompanying phenotypes. PCR amplification and direct sequencing of these monkeys and others showed that the vervet monkeys alone harbored the Ile122 allele, as opposed to the more common Val122 allele in other primates and humans. Histopathological investigations showed cardiac amyloidosis and rigid amyloid fibers in the heart, identical to that observed in aged humans with the allele in question. These deposits were also found in other systems such as the gastrointestinal tract, adipose tissue, lung, tongue, and vascular walls, also mirroring the multiple locations they were found in humans. Immunoblotting confirmed that amyloid proteins extracted from the cardiac specimens reacted with anti-TTR antibody. Other cardiac symptoms were observed that mirror those in humans, such as arrythmia and reduced ehection fraction. Real-time PCR showed that these monkeys and humans shared the majority of TTR expression patterns. Recombinant monkey TTRs showed a greater tendency to dissociate to monomers under the influence of urea-mediated denaturation stress than recombinant TTR of the cynomolgus monkey, which had the Val122 allele. ThT-binding assay also showed a higher number of amyloid fibers in the recombinant than the cynomolgus.

ModelVariant: NM_000371.4(TTR):c.424G>A (p.Val142Ile)

ClinVar: 13426, https://www.ncbi.nlm.nih.gov/clinvar/variation/13426/

NonHumanModel: Mouse (Mus musculus)

GeneAlteration: CRISPR-Cas9 gene editing was used to produce gene-edited mouse zygotes. This was accomplished by designing a guide RNA (gRNA) with the CRISPR design tool and microinjecting the gRNA complex along with Cas9 mRNA and a ultramer repair template including the single deletion into mouse zygotes. This directs double-strand breaks in the genome with homology directed repair causing the precise genome edit necessary. These were injected into psuedo-pregnant C57BL/6J mice. After birth, tail DNA was genotyped via PCR and Sanger seuqencing to confirm the mutation. One heterozygous 525delT mouse was crossed and the offspring backcrossed onto DBA/2J background until the F5 generation confirmed homozygous for the severe LTBP4 allele which results in a more severe disease progression. RT-PCR confirmed the presence of the deletion and loss of γ-sarcoglycan was confirmed via immunoblot analysis and immunofluorescence microscopy.

ModelPhenotype: HP:0003202, HP:0031237, HP:0030951, HP:0003713, HP:0011987, HP:0003557, HP:0003236, HP:0003323, HP:0005957 (Skeletal muscle atrophy, Internally nucleated skeletal muscle fibers, Skeletal muscle fibrosis, Muscle fiber necrosis, Ectopic ossification in muscle tissue, Increased variability in muscle fiber diameter, Progressive muscle weakness, Breathing dysregulation)

ModelFreeText: Decreased cross-sectional area of myofibers, Increased immune infiltrate, Increased dye uptake into compromised myofibers

HumanPhenotype: HP:0003202, HP:0030951, HP:0003713, HP:0003236, HP:0003323, HP:0005957 (Skeletal muscle atrophy, Skeletal muscle fibrosis, Muscle fiber necrosis, Elevated serum creatine kinase, Progressive muscle weakness, Breathing dysregulation)

HumanFreeText: N/A

ModelEvidence: This model has many positive aspects compared to the default mouse model, although it also has some challenges to overcome. In terms of the generation, CRISPR-Cas9 gene editing via HDR is a relatively simple way to modify the genome as needed and create only the variant of interest while leaving the rest untouched. This results in a knock-in with a reasonable assurance that whatever phenotypes are displayed stem solely from the change in the SGCG gene. Specifically the muscle atrophy, elevated serum creatine kinase, progressive weakness (half the strength of controls at 4 months), and signifiacntly increased muscle fibrosis/necrosis are all hallmarks of the human LGMD presentation and are recapitulated here. However, the presence of a known muscular dystrophy-modifying background raises the question of whether some of these phenotypes would not be seen in a mouse with the C57BL/6J background. Unfortunately this is not answered in the paper, so it introduces some doubt as to the total validity of the results.

ModelVariant: NM_000231.2(SGCG):c.525del (p.Phe175fs)

ClinVar: 189243 https://www.ncbi.nlm.nih.gov/clinvar/variation/189243/

NonHumanModel Mus musculus

GeneAlteration Transgenic mouse-modified gene (C57BL/6XSJL) inserted into fertilized mouse eggs

ModelPhenotype HP:0003124 Hypercholesterolemia

HumanPhenotype HP:0003124 Hypercholesterolemia

ModelEvidence Demonstrated low binding affinity of mouse and patient LDL compared to healthy control (fig. 4). Also, tested to make sure other common ligands of the receptor did not compete with the mutant apoB and sway the data (fig. 5 B,C,D). Tested to be sure that differential binding was not influenced by expression levels of apoB in R3500Q mutant using 2 other mutants (R3500G, R3500K) with different expression levels (fig. 5 A.

ModelVariant NM_000384.2(APOB):c.10580G>A (p.Arg3527Gln), ClinVar ID: 17890

ExperimentName: Mouse model with hemizygous disruption of the GPR143 ortholog Oa1

NonHumanModel: Mus musculus

GeneAlteration: A hemizygous mouse model of Oa1 knockout was generated by replacement of exon 1 (including the start codon) with a cassette to facilitate selection.

ModelPhenotype: HP:0007894 (Hypopigmentation of the fundus), HP:0025551 (Optic nerve misrouting), Giant melanosomes in retinal pigment epithelial cells

HumanPhenotype: HP:0000639 (Nystagmus), HP:0003593 (Infantile onset), HP:0007663 (Reduced visual acuity), HP:0001361 (Nystagmus-induced head nodding), HP:0000646 (Amblyopia), HP:0000483 (Astigmatism), HP:0000613 (Photophobia), normally pigmented skin and hair, HP:0005592 (Giant melanosomes in melanocytes), HP:0007750 (Hypoplasia of the fovea), HP:0007894 (Hypopigmentation of the fundus), HP:0025551 (Optic nerve misrouting)

ModelEvidence: Although the coat, eye color, and ERG responses of the mice were unaffected, the mice match the human patients in that they exhibit hypopigmentation of the fundus (Fig. 2), optic fiber misrouting at the chiasm, and expansion of individual melanosomes into giant melanosomes within cells of the RPE (Figures 2, 3). The mice match the mode of inheritance from the human patients.

ModelVariant: This model features disruption of Oa1 by knockout, but does not harbor a mutation equivalent to a variant from a human patient.

ExperimentName: Chlamydomonas mutant model of IFT140 loss-of-function

NonHumanModel: Chlamydomonas reinhardtii

GeneAlteration: The Ift140 mutant model has disruption of the Chlamydomonas gene by insertion of the paromomycin resistance gene AphVIII between bases 8234 and 8235 of the IFT140 gene (in exon 21 of 28).

ModelPhenotype: The mutant exhibits short flagella due to slower flagellar regeneration as well as absence of IFT43 and IFT122 (IFT-A proteins) from the peri-basal body (shown by immunofluorescent co-localization with α-tubulin).

HumanPhenotype: The human patients exhibit the absence of cilia from fibroblasts

ModelEvidence: The cellular defects of the model in flagellar regeneration/assembly (Figures 6A,6C) parallel the absence of cilia from a high proportion of patient fibroblasts. The model also helps explain this defect by showing the underlying cause; the absence of IFT-A complex components from the peri-basal body region (Figure 5E-5F).

ModelVariant: The model does not feature any of the variants observed in human patients.

ExperimentName: Mouse knockout model of Rpgr loss-of-function

NonHumanModel: Mus musculus

GeneAlteration: The model has targeted hemizygous (male) or biallelic (female) disruption of the mouse Rpgr gene by insertion of a neomycin resistance cassette to replace exons 4 through 6 with a resistance cassette and generate a null variant.

ModelPhenotype: HP:0030612 (Abnormal retinal morphology on macular OCT), partial mislocalization of blue and green cone opsins to the inner segment, reduced rhodopsin content in the outer segment, HP:0000546 (Retinal degeneration), HP:0030609 (Photoreceptor layer loss on macular OCT), HP:0030610 (Photoreceptor outer segment loss on macular OCT), disorganization of disk membranes, normal connecting cilia morphology, HP:0030483 (Reduced amplitude of dark-adapted bright flash electroretinogram a-wave), HP:0008275 (Abnormal light-adapted electroretinogram),

HumanPhenotype: HP:0007642 (Congenital stationary night blindness), HP:0007994 (Peripheral visual field loss), HP:0000529 (Progressive visual loss), HP:0000365 (Hearing impairment), HP:0002205 (Recurrent respiratory infections), HP:0011109 (Chronic sinusitis), HP:0000388 (Otitis media), HP:0002837 (Recurrent bronchitis), HP:0012263 (Immotile cilia), HP:0005938 (Abnormal respiratory motile cilium morphology)

ModelEvidence: The model has been well-characterized at the ocular level and triggers molecular and photoreceptor cell defects (Figures 4a, 4b, 5, 6, 7a, and 7b) that are consistent with human patient features such as night blindness, central visual field loss, and peripheral visual field loss.

ModelVariant: The model does not feature a variant equivalent to one observed in human patients.

ExperimentName: Mouse homozygous mutant model of partial IFT140 loss-of-function

NonHumanModel: Mus musculus

GeneAlteration: The Cauli mouse model has biallelic disruption of the mouse Ift140 gene introduced by mutagenesis using N-ethyl-N-nitrosourea. The mutation is a missense change is c.2564T>A (p.Ile855Lys) in Ift140.

ModelPhenotype: HP:0034241 (Prenatal death), HP:0030769 (Exencephaly), HP:0002414 (Spina bifida), HP:0001999 (Abnormal facial shape), HP:0002648 (Abnormality of calvarial morphology), HP:0011297 (Abnormal digit morphology), HP:0001627 (Abnormal heart morphology), HP:0033334 (Abnormal embryonic development, specifically defects in somite patterning), HP:0000528 (Anophthalmia), HP:0001829 (Foot polydactyly), HP:0000194 (Open mouth), HP:0000772 (Abnormal rib morphology), HP:0000896 (Rib exostoses), HP:0001789 (Hydrops fetalis), HP:0001654 (Abnormal heart valve morphology), HP:0010290 (Short hard palate),

HumanPhenotype: HP:0001156 (Brachydactyly), HP:0010579 (Cone-shaped epiphysis), HP:0000556 (Retinal dystrophy), HP:0001591 (Bell-shaped thorax), HP:0000773 (Short ribs), HP:0000107 (Renal cyst), HP:0001252 (Hypotonia), HP:0001263 (Global developmental delay), HP:0001363 (Craniosynostosis), HP:0005054 (Metaphyseal spurs), HP:0010454 (Acetabular spurs), HP:0000083 (Renal insufficiency), HP:0002093 (Respiratory insufficiency), absent cilia in fibroblasts

ModelEvidence: The mode of inheritance in this model matches the biallelic/homozygous mode of inheritance observed in human disease. While the defects in the mouse model are more severe than those of the human patients, shared features include rib cage anomalies (Figure 2), digit anomalies (Figure 4), disruption of eye development (fully penetrant, described in text only), and severe morphological anomalies of the primary cilia in the limb buds (Figure 1G). While the model was generated using a mutagen, it is important to note that the targeted homozygous null mutant in Ift140 recapitulates the features of the model, albeit with enhanced severity. This confirms that the model's mechanism of pathogenicity is incomplete loss of Ift140 function. The localization of Ift140 protein to the base and tip of primary cilia in the limb bud is also consistent with the known function in humans (Figure 5F).

ModelVariant: The model does not feature any of the variants observed in human patients. Instead, the mutation is a missense change, c.2564T>A (p.Ile855Lys) in Ift140. The corresponding residue in human IFT140 is Thr854.

Mouse model based on ERG defects induced by Kcnj13 shRNA injection (packaged in lentiviral particles)

ExperimentName: Two dog models of Rpgr loss-of-function

NonHumanModel: Canis lupus familiaris

GeneAlteration: The two models have disruption of the dog Rpgr gene by the c.1028_1032del frameshift variant or the c.1084_1085del frameshift variant, respectively.

ModelPhenotype: Normal photoreceptors until young adulthood in one model, HP:0000546 (Retinal degeneration), Photoreceptor outer segment cell degeneration, HP:0030483 (Reduced amplitude of dark-adapted bright flash electroretinogram a-wave), HP:0008275 (Abnormal light-adapted electroretinogram), relative sparing of cones in both models, HP:0000618 (Blindness)

HumanPhenotype: HP:0007642 (Congenital stationary night blindness), HP:0007994 (Peripheral visual field loss), HP:0000529 (Progressive visual loss), HP:0000365 (Hearing impairment), HP:0002205 (Recurrent respiratory infections), HP:0011109 (Chronic sinusitis), HP:0000388 (Otitis media), HP:0002837 (Recurrent bronchitis), HP:0012263 (Immotile cilia), HP:0005938 (Abnormal respiratory motile cilium morphology)

ModelEvidence: The two models have been well-characterized at the ocular level and exhibit ERG abnormalities (Fig. 4IB1-3) and degeneration of visual cells and outer segment disorganization, leading to end-stage retinal disease (Fig.4IIE-4IIH). These phenotypes are consistent with human patient features such as night blindness, central visual field loss, and peripheral visual field loss.

ModelVariant: The models study naturally occurring variants that do not have equivalent / orthologous variants reported in human patients.

ExperimentName: Naturally occurring bbs-7 loss-of-function C. elegans model

NonHumanModel: C. elegans

GeneAlteration: The model animals harbor a naturally occurring homozygous nonsense variant at nucleotide 2899 within the bbs-7 locus.

ModelPhenotype: short cilia, defective chemotaxis, defective intraflagellar transport, IFT mislocalization

HumanPhenotype: HP:0001956 (Truncal obesity), HP:0000618 (Blindness), HP:0001249 (Intellectual disability), HP:0001631 (Atrial septal defect), HP:0001640 (Cardiomegaly), HP:0100598 (Pulmonary edema), HP:0012584 (Bilateral renal hypoplasia), HP:0004719 (Hyperechogenic kidneys), HP:0003774 (Stage 5 chronic kidney disease), HP:0000580 (Pigmentary retinopathy), HP:0000648 (Optic atrophy), HP:0008043 (Retinal arteriolar constriction), HP:0007737 (Bone spicule pigmentation of the retina), HP:0007754 (Macular dystrophy)

ModelEvidence: This is a naturally occurring C. elegans model of biallelic bbs-7 disruption. The mutant animals exhibit reduced chemotaxis (dependent on two chemosensory neurons, Figure 2E), shorter cilia (Figure 3), defective localization of IFT particles (Figure 4), and reduced intraflagellar transport (Figure 5). Rescue of chemotaxis with expression of the wild-type C. elegans bbs-7 gene directly linked the defect with bbs-7 (Figure 2E).

ModelVariant: This model did not introduce a disease-associated variant known from an affected human patient, but rather studied a naturally occurring and apparent null variant disrupting bbs-7 expression.

ExperimentName: The eclipse / els zebrafish mutant harbors a missense variant in the PDE6C ortholog pde6alpha'.

NonHumanModel: Danio rerio

GeneAlteration: The model animals are homozygous for a missense variant p.Met175Arg.

ModelPhenotype: HP:0008020 (cone dystrophy), HP:0030465 (Undetectable light-adapted electroretinogram), normal dark-adapted ERG, rapid and progressive elimination of cone photoreceptors from adult retinas

HumanPhenotype: HP:0030465 (Undetectable light-adapted electroretinogram), HP:0030534 (Abnormal best corrected visual acuity test), HP:0000551 (Color vision defect), HP:0000613 (Photophobia), HP:0000639 (Nystagmus), HP:0007401 (Macular atrophy), HP:0000545 (Myopia)

ModelEvidence: This is a naturally occurring zebrafish model that matches the mode of inheritance from the human patients and exhibits lack of light-adapted ERG responses (Figures 1K, 1M) and normal dark-adapted ERG responses. Optokinetic responses mediated by rod function were normal, while those mediated by cone function were absent (Figure 4). The mice also exhibit rapid and progressive loss of cone photoreceptors from retinal sections (Figures 1G, 1I) and abnormal shape of the photoreceptor outer segment (Figure 1C). Rod markers are maintained while cone markers are absent from adult animals (Figure 4).

ModelVariant: This model did not introduce a disease-associated variant known from an affected human patient, but rather studied a naturally occurring variant disrupting the PDE6alpha' locus orthologous to human PDE6C.

ExperimentName: Continued studies of mouse model with hemizygous disruption of the GPR143 ortholog Oa1

NonHumanModel: Mus musculus

GeneAlteration: A hemizygous mouse model of Oa1 knockout was previously generated by replacement of exon 1 (including the start codon) with a cassette to facilitate selection (PMID: 11092754).

ModelPhenotype: HP:0003593 (Infantile onset), HP:0005592 (Giant melanosomes in melanocytes), severely reduced microtubule-based motility in melanosomes

HumanPhenotype: HP:0000639 (Nystagmus), HP:0003593 (Infantile onset), HP:0007663 (Reduced visual acuity), HP:0001361 (Nystagmus-induced head nodding), HP:0000646 (Amblyopia), HP:0000483 (Astigmatism), HP:0000613 (Photophobia), normally pigmented skin and hair, HP:0005592 (Giant melanosomes in melanocytes), HP:0007750 (Hypoplasia of the fovea), HP:0007894 (Hypopigmentation of the fundus), HP:0025551 (Optic nerve misrouting)

ModelEvidence: The mice match the human patients in that they exhibit congenital onset of cytological abnormalities (PMID: 16303920), These were previously shown in the RPE and are here shown in the melanocytes as well (Figure 3). Most importantly, this study shows a defect in microtubule-based melanosome motility (Figure 7), indicating an underlying mechanism for the disease.

ModelVariant: This model features disruption of Oa1 by knockout, but does not harbor a mutation equivalent to a variant from a human patient.

Does model have relevance to bone density or retinal function?

ExperimentName: Transgenic zebrafish expressing human GUCY2D R838S

NonHumanModel: Danio rerio

GeneAlteration: A human GUCY2D transgene encoding either the wild-type protein or the the R838S substitution was placed under the control of the cone-specific gnat2 promoter and injected into zebrafish embryos, creating a transgenic model with cone-specific expression of the variant.

ModelPhenotype: HP:0410280 (Pediatric onset), HP:0000479 (Abnormal retinal morphology), HP:0030609 (Photoreceptor layer loss on macular OCT)

HumanPhenotype: HP:0000548 (Cone/cone-rod dystrophy), HP:0007663 (Reduced visual acuity), HP:0007994 (Peripheral visual field loss), HP:0000613 (Photophobia), HP:0011504 (Bull's eye maculopathy), HP:0030465 (Undetectable light-adapted electroretinogram), (Photoreceptor layer loss on macular OCT), HP:0410280 (Pediatric onset)

ModelEvidence: The model system approximately recapitulates the mode of inheritance (autosomal dominant) of the human disease state. Overexpression effects of the transgene were ruled out by comparison to the wild-type transgenic control, which did show some differences from the non-transgenic control. At the ocular level, larval optokinetic response (visual behavior) was normal. At the cellular/microscopic level, cone morphology was disrupted (Figures 2, 3, 4) and cone density was reduced (Figure 2), along with the thickness of the (rod) outer nuclear layer (Figure 5).

ModelVariant: NM_000180.4(GUCY2D):c.2512C>A (p.Arg838Ser) (ClinVar: 98568)

Reduced amplitude of dark-adapted bright flash electroretinogram a-wave HP:0030483 (Figure 4), Reduced OCT-measured macular thickness HP:0030607 (Figure 2), immunoblot analysis showing reduced L185P in retinas, indicating instability or reduced transport to the outer segment (Figure 5b).

NonHumanModel: Mouse (Mus musculus)

GeneAlteration: A fragment covering exons 4-8 of the SLC1A3 locus was subcloned with the P290R seuqnece being inserted via PCR into the end of Exon 7. Thse clones were injected into blastocysts of C37BL/6N mice with these generatingfoster mice and chimeric mice being crossbred to excise the neomycin casette. Due to the high mortality rate, the surviving mice harboring the variant were backcrossed to 129/SvJ for a more robust mouse and higher survival rate for study.

ModelPhenotype: MP:0002064, MP:0001393, MP:0010387, MP:0008925, MP:0002182, MP:0000877, MP:0010170, MP:0014185 (Seizures, Ataxia, Abnormal Bergmann glial cell morphology, Increased cerebellar granule cell number, Abnormal astrocyte morphology, Abnormal Purkinje cell morphology, Abnormal glial cell apoptosis, Cerebellum atrophy)

ModelFreeText: Slower firing of purkinje neurons

HumanPhenotype: HP:0001251, HP:0002076, HP:0001250 (Ataxia, Migraine, Seizure)

HumanFreeText: N/A

ModelEvidence: The first set of mutant knock-in mice were subject to generalized seizures and death before the weaning period, requiring a backcross onto the 129/SvJ strain in order to reduce lethal seizure activity and delay the onset. Even so, mutant mice demonstrated significant phenotypes indicative of human Episodic Ataxia including epilepsy, ataxia, and reduced motor/gait coordination. In order to determine the pathogenc mechanism, cerebellar Bergmann glia cells were examined to find a pronounced age-dependent reduction of cell numbers between P10 and P20. Immunostaining showed decreased numbers of somata and expression, demonstrating that the EAAT1 mutants were subject to cell death. Granule cell migration was also impaired during development, coupled with invasion of reactive astrocytes into the molecular layer demonstrating attempted repair. Following from this change, Purkinje neurons were examined and found to have been reduced and the morphology altered in mutant mice. As the P290R variant is known to increase EAAT1 anion currents in heterologous expression systems, measurement of these currents in mouse Bergmann glia cells showed significantly increased current, decreased Cl- concentration, and a resulting higher TUNEL expression in these cells, indicating earlier apoptosis events of these cell types. Spiking activities and developmental acceleration is absent in these cell types, likely due to progressive deterioration. This was verified by an observation of cerebellar size, where mutant cerebellar tissue showed generalized degeneration compared to the WT mice.

ModelVariant: NM_004172.5(SLC1A3):c.869C>G (p.Pro290Arg)

ClinVar: 9441, https://www.ncbi.nlm.nih.gov/clinvar/variation/9441/

NonHumanModel: Mouse (Mus musculus)

GeneAlteration: Mutations were induced in mice germline cells at a rate near 10^-3 per locus via an alkylating agent called ethylnitrosourea. Inbred BTBR males were treated with this agent and bred to normal BTBR females. Three hundred and fifty progeny were screened for mutations that did not complement the previous model PAH_enu1 and if present bred to a previous homozygote and tested for hyperphenylalaninemia. A PHE clearance test was performed in questionable cases. For those that tested positive the carrier parents were mated to a normal BTBR partner to establish a cogenic mutant line. Western blot confirmed reduced to absent CRM in liver.

ModelPhenotype: HP:0007513, HP:0000707, HP:0005982, HP:0100610, HP:0004923, HP:0001510, HP:0000252 (Generalized hypopigmentation, Abnormality of the nervous system, Reduced phenylalanine hydroxylase activity, Maternal hyperphenylalaninemia, Hyperphenylalaninemia, Growth delay, Microcephaly)

ModelFreeText: Serum PHE concentrations were 15x wild-type for PAH_enu2 (23.1 +/- 6.9 mg/dl, 1.5 +/- 0.5 reference) and 14x wild-type for PAH_enu3 (20.3 +/- 5.9 mg/dl, 1.5 +/- 0.5 reference), PAH activity was reduced to <1% wild-type for PAH_enu2 (0 +/- 2 delta O.D. x 10^3/min/mg protein, 40 +/- 6 reference) and <10% wild-type for PAH_enu3 (5 +/- 5 delta O.D. x 10^3/min/mg protein, 40 +/- 6 reference)

HumanPhenotype: HP:0007513, HP:0000707, HP:0005982, HP:0100610, HP:0004923, HP:0000252 (Generalized hypopigmentation, Abnormality of the nervous system, Reduced phenylalanine hydroxylase activity, Maternal hyperphenylalaninemia, Hyperphenylalaninemia, Microcephaly)

HumanFreeText: N/A

ModelEvidence: PAH_enu2 has been further characterized many times and results from a missense variant in PAH (PMID: 9119379). PAH_enu3 has also been further characterized and results from a canonical splicing variant in PAH (PMID:11161825). Both models fully recapitulate the phenotypes we expect to see in phenylketonuria, including the quintessential elevated PHE levels and significantly decreased PAH activity. Also of note is the progressive hypopigmentation, microcephaly, growth delay, and neurological abnormalities which are all seen in human probands without proper intervention. Maternal hyperphenylalaninemia is also recapitulated, with no pups surviving beyond several hours with standard breeding diet when born to a mother with the homozygous genotype. Diets low in PKU resulted in less severe symptoms, similar to low protein diets in human probands.

ModelVariant1: NM_000277.3(PAH):c.788T>C (p.Phe263Ser)

ClinVar: 619150 https://www.ncbi.nlm.nih.gov/clinvar/variation/619150/

ModelVariant2: NM_000277.3(PAH):c.1199+2T>G

ClinVar: 557365 https://www.ncbi.nlm.nih.gov/clinvar/variation/557365/

NonHumanModel: Mouse (Mus musculus)

GeneAlteration: Two constructs were created, containing with the WT human GDH sequence or the H507Y variant along with the rat insulin promotoe and human growth hormone genomic DNA sequence to stabilize the construct and drive β-cell-specific transcription of the cDNA sequence. These were microinjected into fertilized eggs of B6SJLF1 mice, transferred into pseudopregnant females, and PCR-amplified/sequenced to confirm the succesful insertion of the transgene. Offspring were crossed with C57BL/6 mice and generated two lines of mutant along with one line of WT transgenic mice: TG-1, TG-2, and huGDH.

ModelPhenotype: MP:0000189, MP:0008770, MP:0002079, MP:0005309 (hypoglycemia, decreased survivor rate, increased circulating insulin level, hyperammonemia)

ModelFreeText: Higher sensitivity to leucine and glutamine ramp stimulation, Increased ATP/ADP ratios

HumanPhenotype: HP:0001987, HP:0001988, HP:0000825 (Hyperammonemia, Recurrent hypoglycemia, Hyperinsulinemic hypoglycemia)

HumanFreeText: N/A

ModelEvidence: The two lines of mice transgnically modified with the H507Y variant were observed compared to the WT mice. Both lines of mice had notable and spontaneous hypoglyemia, specifically affecting both the mouse survivial rate and fertility compared to the control line. Cultured insulin islets were compared and demonstrated significantly increased insulin secretion when exposed to glutamine as well as showing an increased sensitivity to leucine. This also results in elevated ammonia as a byproduct, since the elevated reaction product also yields NH4+. This directly results to the pathogenic mechanism of H507Y, and other pathogenic GLUD1 variants, in humans. These variants reduce the protein's sensitivity to regulation by GTP, causing increased glutamate oxidation and insulin production by raising the ATP/ADP ratio artifically.

ModelVariant: NM_005271.5(GLUD1):c.1519C>T (p.His507Tyr)

ClinVar: 16121, https://www.ncbi.nlm.nih.gov/clinvar/variation/16121/

NonHumanModel: Mouse (Mus musculus)

GeneAlteration: Two approaches were used to create this model. The first imitated the slow fiber-specific expression of TPM3 by linking the coding region for αTm_slow(Met9Arg) to a human troponin I slow gene that drives expression specifically in these fibers via EcoRI-PstI digest and ligation into a linearized construct. The second, HSA–αTm_slow(Met9Arg), expressed the mutation in fast fibers by ligating a SmaI-BamHI cassette containing the intron and 3′-UTR of SV40 small t antigen directly downstream of the mutant cDNA sequence followed by blunt-end ligation of the HSA promoter into the EcoRV site upstream of the sequence before linearizing into a construct. These constructs were injected into fertilized eggs and screened by southern blot analysis to verify the successful insertion.

ModelPhenotype: HP:0003798, HP:0100303, HP:0100301, HP:0003557, HP:0001324, HP:0011807 (Nemaline bodies, Muscle fiber cytoplasmic bodies, Muscle fiber tubular aggregates, Increased variability in muscle fiber diameter, Muscle weakness, Type 1 muscle fiber atrophy)

ModelFreeText: Disorganized sarcomeres, Increased slow/fast oxidative fibers

HumanPhenotype: HP:0003798, HP:0003557, HP:0001324, HP:0011807 (Nemaline bodies, Increased variability in muscle fiber diameter, Muscle weakness, Type 1 muscle fiber atrophy)

HumanFreeText: Disorganized sarcomeres

ModelEvidence: The Met9Arg mouse models not only clearly recapitulate the phenotypes of nemaline/other myopathies but also provide evidence to suggest possible pathogenic mechanisms of the mutated allele in vivo. Mice expressing the mutated allele display nemaline rods and clear fiber-type disproportion, both of which are hallmarks for their respective diseases. They also displayed progressive muscle weakness starting around 5-6 months of age, a phenotype that matches the childhood-onset muscle weakness and other progressive symptoms common in TPM3-related congenital myopathy patients. Another classic phenotype, atrophy of Type I muscle fibers with a corresponding hypotrophy of Type II fibers was also present in the mice. This may be related to the increased number of slow/fast oxidative fibers in the mutant mice leading to the disruption of normal muscle fiber maturation. The mice also displayed some cytoplasmic bodies and tubular aggregates; these have been observed in varying functional studies and similar features have also been observed in humans.

ModelVariant: NM_152263.4(TPM3):c.26T>G (p.Met9Arg)

ClinVar: 12446 https://www.ncbi.nlm.nih.gov/clinvar/variation/12446/

NonHumanModel: Zebrafish

GeneAlteration: TPM2 complementary DNA was obtained and subcloned in-frame with GFP by PCR using the 5' CMV/SP6 promoter. Site-directed mutagenesis was performed to engineer the DNA with the p.K7del mutation. Afterwards, both types of complementary DNA were injected into stage 1 zebrafish embryos. Myofibers were isolated and analyzed from 4- and 7-day post fertilization zebrafish.

ModelPhenotype: N/A

ModelFreeText: 3x decrease in TPM2 width, Disorganized sarcomeres, Localization of TPM2 to the z-band, Decreased overall sarcomere length, Accumulations of Actinin

HumanPhenotype: N/A

HumanFreeText: Disorganized myofibrils and abnormal Z bands, Disorganized sarcomeres, Nuclear clumps

ModelEvidence: This in vivo zebrafish model reflects several of the muscular phenotypes that are displayed in many nemaline myopathy patients. Although only the myofibres were studied, which does not allow for gross muscular phenotypes to develop, there are clear similarities. The disorganized/shortened sarcomeres are commonly seen in muscle biopsies in patients, as well as actin-based nuclear clumps that accumulate. The z-bands and myofibrils can also be demonstrated in nemaline myopathy patients, although the patterns observed are somewhat dissimilar.

ModelVariant: NM_003289.3:c.14_16delAGA (p.Lys7del)

ClinVar: 140486 https://www.ncbi.nlm.nih.gov/clinvar/variation/140486/

ExperimentName: The Cpfl1 mouse harbors loss-of-function variants in the Pde6c gene.

NonHumanModel: Mus musculus

GeneAlteration: The model animals are homozygous for two different loss-of-function variants predicted to introduce premature stop codons into the Pde6c locus. One is a 116-bp insertion between exons 4 and 5, while the other is a 1-bp deletion in exon 7.

ModelPhenotype: HP:0008020 (cone dystrophy), HP:0030465 (Undetectable light-adapted electroretinogram), normal dark-adapted ERG, rapid and progressive loss of cone photoreceptors from the photoreceptor layer

HumanPhenotype: HP:0030465 (Undetectable light-adapted electroretinogram), HP:0030534 (Abnormal best corrected visual acuity test), HP:0000551 (Color vision defect), HP:0000613 (Photophobia), HP:0000639 (Nystagmus), HP:0007401 (Macular atrophy), HP:0000545 (Myopia)

ModelEvidence: This is a naturally occurring mouse model with lack of light-adapted ERG responses and normal dark-adapted ERG responses (Figure 1). The mice also exhibit rapid and progressive loss of cone photoreceptors from retinal sections (Figure 2).

ModelVariant: This model did not introduce a disease-associated variant known from an affected human patient, but rather studied naturally occurring variants disrupting the Pde6c locus.

ExperimentName: Naturally occurring BBS7 loss-of-function primate model

NonHumanModel: Rhesus macaque

GeneAlteration: The model animals harbor a naturally occurring homozygous frameshift variant at nucleotide 160 within exon 3 of the BBS7 locus.

ModelPhenotype: HP:0000608 (Macular degeneration), HP:0030609 (Photoreceptor layer loss on macular OCT), HP:0000580 (Pigmentary retinopathy), HP:0008046 (Abnormal retinal vascular morphology), progressive kidney disease, HP:0030483 (Reduced amplitude of dark-adapted bright flash electroretinogram a-wave), HP:0030469 (Abnormal dark-adapted electroretinogram), HP:0008275 (Abnormal light-adapted electroretinogram), HP:0002171 (Gliosis), HP:0000083 (Renal insufficiency), HP:0012210 (Abnormal renal morphology), HP:0002119 (Ventriculomegaly), HP:0008734 (Decreased testicular size)

HumanPhenotype: HP:0001956 (Truncal obesity), HP:0000618 (Blindness), HP:0001249 (Intellectual disability), HP:0001631 (Atrial septal defect), HP:0001640 (Cardiomegaly), HP:0100598 (Pulmonary edema), HP:0012584 (Bilateral renal hypoplasia), HP:0004719 (Hyperechogenic kidneys), HP:0003774 (Stage 5 chronic kidney disease), HP:0000580 (Pigmentary retinopathy), HP:0000648 (Optic atrophy), HP:0008043 (Retinal arteriolar constriction), HP:0007737 (Bone spicule pigmentation of the retina), HP:0007754 (Macular dystrophy)

ModelEvidence: This is a naturally occurring Rhesus macaque model of biallelic BBS7 disruption. The mutant animals exhibit hypoechoic kidney lesions (Figure 1), retinal atrophy with lack of retinal vasculature (Figure 3A), RPE atrophy (Figure 3B), severe atrophy of retinal layers by OCT with greater severity centrally (Figure 3C), retinal gliosis (Figure 3D), Severely reduced amplitudes and delayed time courses of both dark-adapted and light-adapted flicker ERG (Figure 4), reduced brain volume (Figure 5B), dilation of the lateral ventricle (Figure 5A), cystic kidney tubules with loss of nephrons replaced with fibrosis, tubule atrophy, and ectasia (Figure 7), reduced size and histological maturity of testes (Table 1), and vision deficits (Table 1).

ModelVariant: This model did not introduce a disease-associated variant known from an affected human patient, but rather studied a naturally occurring and apparent null variant disrupting BBS7 expression.

ExperimentName: bbs1-1 Chlamydomonas have full-length flagella and normal IFT function but are nonphototactic.

NonHumanModel: Chlamydomonas reinhardtii

GeneAlteration: The bbs1-1 model animals have been identified as naturally occurring mutants with deletion of approximately half of the BBS1 gene as well as a separate gene unstream of BBS1.

ModelPhenotype: abnormal flagellar motility (inability to perform phototaxis), flagellar absence of BBSome components (specifically BBS4)

HumanPhenotype: HP:0000639 (Nystagmus), HP:0000510 (Rod-cone dystrophy), HP:0007663 (Reduced visual acuity), HP:0000662 (Nyctalopia), HP:0000518 (Cataract), HP:0008323 (Abnormal light- and dark-adapted electroretinogram), HP:0000107 (Renal cyst), HP:0001513 (Obesity), HP:0010442 (Polydactyly), HP:0002463 (Language impairment), HP:0000026 (Male hypogonadism)

ModelEvidence: The mutants lack the ability to perform phototaxis, which is common among all BBSome mutants tested (described in text but data not shown). Flagella from the mutant show loss of BBS4 localization (Figure 4C). However, flagellar length was normal (Figure 2B) and flagellar regeneration was normal as well (described in text but data not shown).

ModelVariant: This model had a naturally occurring deletion disrupting BBS1 but did not feature knock-in of a known variant from the human patient population.

ExperimentName: Zebrafish knockdown of the GPR143 ortholog OA1

NonHumanModel: Danio rerio

GeneAlteration: A zebrafish model of OA1 loss-of-function was generated by morpholino-based knockdown.

ModelPhenotype: HP:0007703 (Abnormality of retinal pigmentation)

HumanPhenotype: HP:0000639 (Nystagmus), HP:0003593 (Infantile onset), HP:0007663 (Reduced visual acuity), HP:0001361 (Nystagmus-induced head nodding), HP:0000646 (Amblyopia), HP:0000483 (Astigmatism), HP:0000613 (Photophobia), normally pigmented skin and hair, HP:0005592 (Giant melanosomes in melanocytes), HP:0007750 (Hypoplasia of the fovea), HP:0007894 (Hypopigmentation of the fundus), HP:0025551 (Optic nerve misrouting)

ModelEvidence: The zebrafish match one feature of the human patients in that they exhibit abnormalities of retinal pigmentation consistent with the ability of GPR143 loss-of-function to trigger defects in melanosome regulation (Figure 1).

ModelVariant: This model features disruption of OA1 expression by knockdown, and does not harbor a mutation equivalent to a variant from a human patient.

ExperimentName: Canine model of Adam9 loss-of-function

NonHumanModel: Canis lupus familiaris

GeneAlteration: The affected dogs have homozygous disruption of the Adam9 gene by a deletion of regions from exons 15 and 16.

ModelPhenotype: HP:0001105 (Retinal atrophy), HP:0000529 (Progressive visual loss), HP:0000580 (Pigmentary retinopathy), HP:0000662 (Nyctalopia)

HumanPhenotype: HP:0011463 (Childhood onset), HP:0000548 (Cone/cone-rod dystrophy), HP:0007663 (Reduced visual acuity), HP:0001141 (Severely reduced visual acuity), HP:0007994 (Peripheral visual field loss), HP:0000545 (Myopia), HP:0000483 (Astigmatism), HP:0000523 (Subcapsular cataract)

ModelEvidence: The affected dogs have been described as having generalized progressive retinal atrophy. Complete loss of all retinal layers was observed in affected animals (Figures 1H-1P). This matches the mode of inheritance and progressive nature of the human disease state, as well as the retinal abnormalities and visual defects.

ModelVariant: The model harbors a targeted deletion that does not have an equivalent / orthologous variant reported in human patients.

ExperimentName: Mouse model of homozygous Cln5 loss

NonHumanModel: Mus musculus

GeneAlteration: Mice are homozygous for Cln5 loss of function, caused by Insertion of a neomycin resistance cassette eliminating exon 3, resulting in a premature stop codon in exon 4. The presence or absence of a truncated gene product was not assessed.

ModelPhenotype: HP:0003208 (Fingerprint intracellular accumulation of autofluorescent lipopigment storage material), HP:0003205 (Curvilinear intracellular accumulation of autofluorescent lipopigment storage material), HP:0000572 (Visual loss)

HumanPhenotype: HP:0003208 (Fingerprint intracellular accumulation of autofluorescent lipopigment storage material), HP:0003205 (Curvilinear intracellular accumulation of autofluorescent lipopigment storage material), HP:0000572 (Visual loss)

ModelEvidence: The model phenotypes closely match the human patient phenotypes at the microscopic level (characteristic autofluorescent inclusion bodies ) as well as the loss of vision, but do not reproduce neurological features such as seizures, ataxia, loss of motor coordination, mental regression, and behavioral changes.

ModelVariant: While it is unclear whether the mice express a truncated form of Cln5 or whether this form is degraded, the predicted protein product does not represent a particular human variant. The authors speculate that it may be most similar to the NM_006493.4(CLN5):c.522dup (p.Trp175LeufsTer30) variant (PMID:10953198).

NonHumanModel Mus Musculus

GeneAlteration The knock-in strain was generated by homologous recombination of the targeting vector with 129Sv/J embryonic stem cells genome. A 450-bp DNA segment encompassing 5′ UTR and exon 1 of the CASQ2 was used to screen RPCI-21 PAC mouse genomic library. Positive clones were sequenced to define the structure of an 8.5-Kb region encompassing promoter, exon 1, and part of intron 1 of mouse CASQ2. This region was cloned in 3 parts and assembled into the targeting vector pFlrt (supplemental Figure I). The linearized targeting vector was electroporated into 129Sv/J embryonic stem cells. The clone selected with G418 and gancyclovir was injected into C57BL/6NCrL blastocyts and transferred to pseudopregnant CD-1 females. Genotype was determined by sequencing of DNA extracted from tail biopsy specimens (DNasy Tissue Kit, Qiagen).

ModelPhenotype HP:0004758

HumanPhenotype HP:0004758

ModelEvidence Fig. 1 ECG during stimuli shows VT in only the mutant mice

ModelVariant NM_001232.3(CASQ2):c.97C>T (p.Arg33Ter), 41043 link

ExperimentName: Plaa G23V/G23V homozygous mice

NonHumanModel: mus musculus

GeneAlteration: Crispr/Cas9 gene editing was used to successfully mutate the mouse Plaa gene with a patient derived variant, G23V (mouse c. 68G>T) (Figure 3 and Figure S4). From the first round of injections, the obtained 33 mice, in which 3 had the c.68G>T variation alone/ solely. Confirmation of the change was performed by Sanger sequencing in the founder mice.

ModelPhenotype: HP:0004325, HP:0002808, HP:0001337, HP:0012448

HumanPhenotype: HP:0012448

ModelEvidence: Plaa G23V homozygous mice are viable past birth, but cannot survive past 6 months without assistance of feeding, etc (Figure 3B). The mutant show microcephaly (reduced brain volume, Figure 3C). MRI performed on the G23V homozygous mice compared with control wildtype littermates show significantly reduced corpus callosum and cerebellum volumes, indicating reduced white matter (Figure 3E). The cerebellum is noted to have disrupted foliation (figure S5C). The authors note early onset neurodysfunction, including tremor and muscle weakness , showing severe hindlimb clasping, reduced grip strength and altered gait detectable from P14 (Figure 3 and Figure S5).

They authors even went on to cross the Plaa G23V heterozygous mice with Plaa homozygous null mice to create Plaa G23V/- mice that have a more severe phenotype that the homozygous Plaa G23V homozygous, but less severe that the Plaa homozygous null (plaa-/-).

EvidenceShown: Figure 3, Figure S3-6,

ModelVariant: NM_001031689.2(PLAA):c.68G>T (p.Gly23Val)

ClinVar ID: 427941

Score:

Reason: This mouse model represents a patient derived mutation that was knocked directly into the mouse Plaa locus, through use of Crispr/Cas9 gene editing. The mice were shown to have reduced Plaa protein expression (reduced by 70%), and the development of phenotypes consistent with phenotypes observed in individuals. I have therefore, increased the score based on the evidence provided.

Score: 3